Insect Invasion!

Billions of noisy bugs called cicadas appear along the East Coast after 17 years underground

After bursting from the ground, cicadas leave behind their old shells. (Thomas Marent / Minden Pictures)

For 17 years they lay hidden underground, waiting to burst from the soil. No, they’re not zombies. They’re a type of bug called cicadas (suh-KAY-duhs). And in the next few days and weeks, billions of these creepy crawlers, known as Brood II cicadas, are due to invade states across the Northeast.

Even though the cicadas will die off a few weeks after we first see them, they actually have the longest life span of any known insect. They just happen to spend most of their lives underground. For much of the time, young cicadas live deep beneath the soil. They suck juices from plant roots to survive until they’re fully grown. Then, once the temperature of the soil reaches 64 degrees Fahrenheit, they crawl out to mate and lay eggs.

Luckily these red-eyed critters are harmless. But they sure are noisy. That’s because male cicadas “sing” to attract females. They do this by flexing their tymbals, drumlike organs (internal body parts) found in their stomachs. This produces a clicking sound. When thousands of cicadas are flexing their tymbals all at once, it can get pretty loud!

THE CYCLE CONTINUES

Brood II cicadas emerge from the ground only once every 17 years, swarming the skies from North Carolina to Connecticut. But this brood of cicadas is just one of many. A brood of cicadas is a group of cicadas that are born in the same year.

Nearly every year, a different brood emerges in different states. There are at least a dozen broods in all. Last year, a group of cicadas called Brood I invaded Virginia, West Virginia, and Tennessee.

The life cycle of the current Brood II cicadas began back in 1996. After they hatched from their eggs in tree branches, they headed for the ground. There, they were able to remain safe from birds that might eat them. In the coming weeks, the cicadas will finally be mature enough to dig their way out from the soil to mate.

By the time summer rolls around, the adult cicadas will begin dying off. But the cycle will continue. Their babies will burrow underground, where they will remain hidden for the next 17 years.